SEQUENCE DETERMINATION OF THE P-GENE OF SIMIAN VIRUS-41 - PRESENCE OF IRREGULAR DELETIONS NEAR THE RNA-EDITING SITES OF PARAMYXOVIRUSES

The complete nucleotide sequence of the P gene of simian virus 41 (SV41) was determined. The gene was found to be 1406 nucleotides long and to contain a relatively small open reading frame encoding a cysteine-rich V protein with a calculated M(r) of 24 076. We have demonstrated that RNA-editing events occur in SV41 P gene transcripts and that the ratio of edited mRNAs to faithfully copied mRNA (P-mRNA : V-mRNA) is about 1 : 5 at either 24 or 40 h post-infection. The mRNA with two G insertions was capable of encoding a P protein of 395 amino acids with a predicted M(r) of 41992. A kinetic study of P and V proteins by Western blot analysis showed that in virus-infected cells the amounts of both proteins were almost equal although the V-mRNA was considerably more abundant than the P-mRNA. Alignment of the SV41 P and V proteins with those of nine other paramyxoviruses demonstrated that irregular gaps were present around the RNA-editing sites.